Abstract:This study aimed to optimize the purification process of polysaccharides from black jerusalem artichoke.An orthogonal experimental design was used to optimize the extraction process by combining the Sevage，macroporous resin，and DEAE fiber column methods.The polysaccharides in black jerusalem artichoke were characterized using infrared spectral analysis and the carbohydrate composition was determined.Probiotics activity of black jerusalem artichoke polysaccharides was studied by Lactobacillus in vitro culture.The optimum conditions of extraction were 80 °C，60 min，and 1∶15（g/mL）.Infrared spectral analysis indicated the presence of a sugar ring structure and β-glucopyranoside bonds in the black jerusalem artichoke polysaccharides.Fructose，glucose，sucrose，and fructooligosaccharide were the main components with concentrations of 11.81，1.86，9.51g/100g，and15.77g/100g.The prebiotic index of black jerusalem artichoke polysaccharide without monosaccharide on Lactobacillus plantarum strain ZL9 and Lactobacillus casei strain GL6 was above 0.80，which can effectively promote the proliferation of both strains and showed good prebiotic activity in vitro.